On the design of a broadband low impedance load mitigating coupling unit for efficiency OFDM signal power transfer maximization through the PLC network

In order to establish high-speed packet based powerline communication systems, carrier frequencies above 1 MHz are required. Unfortunately, the powerline channel is significantly dispersive at the transmission rates needed for broadband access. Therefore, high computational demand is placed on the receiver to combat some interference. The orthogonal frequency division multiplexing (OFDM) was proposed as a new and efficient method to overcome this problem. However, the OFDM transmitter requires a highly linear operating environment. This paper examines the design of an optimized coupling unit which is able to provide wideband mitigation of the effects of low impedance loads on PLC at frequencies ranging from 0.1 to 30 MHz. Maximization of the power transferred from the upstream to downstream communication equipment is the main objective of the present work. Some experimental measurements have been performed at residential and industrial environments in China. Motivations to conduct this experiment are given, some compromise was obtained and results are presented in this paper.